Can't create a template with private comments (internal) and can't access issue security level

Hello, when creating a template I can't show private comments nor issue security level.

The only thing I found about the comments is in this next link:
https://www.meta-inf.hu/display/PLUG/Add+Issue+Comments+to+Emails

However, there's only info about $!publicComments.

How can I have ALL the comments in the template, and how can i access the JIRA issue security level?

Thanks in advance